KR0138116B1 - Method for discriminating authenticity of a ball and an appartus therefor - Google Patents

Abstract

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Description

Banknote Identification Method and Apparatus

1 is a schematic side view showing the positional relationship of a light emitting diode, two photodiodes and a polarizing filter in a banknote identifying apparatus according to a first embodiment of the present invention.

2 is a block circuit diagram showing an electrical circuit portion of the apparatus of the first embodiment.

3 is a block circuit diagram showing an electric circuit section of the apparatus of the second embodiment of the present invention.

4 is a schematic side view showing the positional relationship of a light emitting diode, two photodiodes, and a polarizing filter in a banknote identification device according to a third embodiment of the present invention.

5 is a block circuit diagram showing an electrical circuit portion of the apparatus of the third embodiment.

6 is a flowchart of a control program executed by the microcomputer of FIG.

* Explanation of symbols for main parts of the drawings

1: banknote 2: light source,

3a, 3b: photodiode 4: polarization filter,

5a, 5b: current / voltage conversion circuit,

6: differential amplification circuit 7: voltage comparison unit,

8: split circuit 9: solenoid.

The present invention relates to a banknote identification method and an apparatus in a vending machine, an automatic service machine, a money changer, an automatic deposit machine, and the like.

In vending machines and the like, it is necessary to determine the authenticity of the inserted banknotes. Thus, conventionally, for example, a light source for irradiating light to a banknote and a light receiving element for receiving reflected light on the surface of the banknote or transmitted light passing through the banknote are provided, and the authenticity of the banknote is identified according to the output level of the light receiving element. A banknote identifier is mounted on the machine. In addition, the reflected light is distinguished and detected by two kinds of color components, and the color of the banknote is discriminated according to the detection level for each color component, thereby identifying the authenticity of the banknote. (Japanese Patent Laid-Open No. 62-) 296292).

In addition, it is known that counterfeit bills obtained by color copying real banknotes are identified in real banknotes according to the output of the light receiving element receiving light reflected by the surface of the banknote and the output of the light receiving element receiving the reflected light. National patent publication no. 62-276685).

However, the characteristics of the light source and the light receiving element vary according to the change of the ambient temperature, and on one side of the input banknote, there are fluctuation factors such as new and old, old, wrinkled and unevenness of banknotes.

Therefore, when identifying the authenticity of banknotes according to the output of the light receiving element, it is difficult to set the reference level. In other words, if the reference level is set close to the level of the real banknote and strictly set, the real banknote may be misidentified as a counterfeit banknote. On the contrary, if it is set close to the level on the counterfeit bill side, the counterfeit bill may be mistaken as a real bill. As described above, according to the prior art, it is difficult to eliminate the misjudgment, and in particular, it is difficult to accurately identify the counterfeit money and the real banknote obtained by color copying the real banknote.

An object of the present invention is to change the characteristics of the light source and the light-receiving device of the banknote identification device according to the ambient temperature fluctuation according to the new principle of discriminating the authenticity of the banknote according to the difference in the degree of glossiness of the banknote surface between the counterfeit bill and the real banknote. The present invention provides a banknote identification method and apparatus capable of accurately identifying a variety of counterfeit bills, including real bills and counterfeit bills obtained by color copying of the bills without being affected by wrinkles and stains.

The banknote identification method of this invention detects the light quantity of the reflected light in the said banknote containing (1) the step which irradiates light to a banknote at a predetermined incidence angle, (2) the component polarized at the time of reflection at the surface of the said banknote. Step (3) Detecting the light amount of the reflected light from which the polarization component is removed and (4) The degree of gloss on the surface of the banknote is detected according to the light amount of the reflected light detected in the steps (2) and (3), respectively. This includes the step of determining the authenticity of the banknote.

The banknote identification device of the present invention is a light source for irradiating light on a banknote at a predetermined angle of incidence, and a first light receiving element arranged to be capable of directly receiving the reflected light from the banknote and generating a first electric signal that changes according to the amount of received light. And a second light receiving element for arranging the reflected light so as to receive the light and generating a second electrical signal that changes according to the amount of reflected light received through the polarization filter, and the propagation of the reflected light between the banknote and the second light receiving element. A polarization filter for removing components of the light disposed on a path and flattened upon reflection on the banknote surface, and the degree of gloss of the banknote surface is detected according to the first and second electrical signals, thereby And discrimination means for determining authenticity.

Another banknote identification device of the present invention is a light source for irradiating light to a bill at a predetermined angle of incidence, a light receiving element for receiving the reflected light from the bill to generate an electrical signal that changes according to the amount of light received, between the bill and the light receiving element Movement is freely disposed between a first position interposed on the propagation path of the reflected light and a second position retracted from the propagation path of the reflected light, and operable to remove components of the polarized light upon reflection at the bill surface The polarization filter, driving means for moving the polarization filter between the first position and the second position, and the electrical signal generated when the polarization filter takes the first and second positions, respectively. And discrimination means for detecting the degree of glossiness on the surface of the banknote and thereby determining the authenticity of the banknote.

The banknote identification device according to the first embodiment of the present invention is mounted on, for example, a vending machine, and identifies the authenticity of the banknotes that have been put into the vending machine and conveyed to a predetermined position in the banknote identification device.

Referring to FIGS. 1 and 2, the banknote identification device includes a light source for irradiating light on a predetermined portion of the surface of the input banknote 1 at a predetermined incident angle α, for example, a light emitting diode 2 for generating visible light. ) And the first and second light-receiving elements for generating electric signals that vary in accordance with the amount of received light are arranged to receive the reflected light reflected at the reflection angle β (= α) on the surface of the banknote 1. Doing. This positive light receiving element is formed of, for example, first and second photodiodes 3a and 3b formed adjacent to one chip. And a polarization filter 4 for blocking the polarization component of the polarized light upon reflection on the banknote surface receives the second photodiode 3b on the propagation path of the reflected light between the banknote surface and the second photodiode 3b. It is located in front of the face. The entrance angle α needs the degree of polarization of the light, which is set to an angle within a predetermined angle region, for example, 45 degrees or more, so that the banknote identification device exhibits the necessary identification performance. It is.

As shown in Fig. 2, the output terminals of the photodiodes 3a and 3b of Figs. 1 and 2 are connected to the input terminals of the first and second current / voltage conversion circuits 5a and 5b, respectively. The output terminals of both circuits 5a and 5b are connected to two input terminals of the differential amplifier circuit 6, respectively. The output terminal of the circuit 6 is connected to one input terminal of the voltage comparison circuit 7, and the discrimination reference voltage Vs is applied to the other input terminal of the circuit 7.

Next, the operation of the above-described banknote identification device will be described.

When the banknote 1 is put into the vending machine, the conventional banknote conveying apparatus (not shown) of the banknote identification device and the sensor system cooperate to convey the banknote 1 to a predetermined position in the banknote identifying apparatus shown in FIG. Hold on location temporarily. Subsequently, under the control of a control device (not shown) provided in a vending machine or a bill identification device, a driving circuit (not shown) of the bill identification device is operated so that the light emitting diode 2 is turned on so that visible light is determined on the surface of the bill (1). The site is irradiated with an incidence angle α of about 60 degrees.

A part of the irradiation light is reflected at the reflection angle β on the banknote surface and inside, and propagates the air toward the first and second photodiodes 3a and 3b. In addition, the remaining portion of the irradiation light is absorbed by the banknote 1 or passes through the banknote. The reflected light is directly received without being substantially attenuated by the first photodiode 3a having no optical inclusion between the banknote 1 and.

Here, the reflectance of the light on the surface of the banknote 1 changes depending on the degree of glossiness on the banknote surface, and the reflected light on the real banknote surface lacking the gloss is low in light, and is rich in gloss-rich counterfeit money obtained by color copying the real banknote The amount of light reflected by the surface of the surface simply referred to as counterfeit money) is large. Therefore, the output current Da varying in accordance with the amount of light received by the first photodiode 3a that receives the reflected light from the surface of the banknote 1 and the inside of the banknote 1 is a small value for a real banknote, and a large value for a counterfeit bill. Take it.

On the other hand, the reflected light from the banknote surface directed to the second photodiode 3b reaches the polarization filter 4 disposed in front of the photodiode 3b before reaching the second photodiode 3b.

Light in the light emitting diode 2 is at least partially polarized in a direction parallel to the banknote surface, ie in the horizontal direction, upon reflection from the surface of the banknote 1. The polarization filter 4 prevents the passage of the polarized component with the horizontal amount of reflected light. As a result, the light quantity of the reflected light which removed the polarization component received by the 2nd photodiode 3b is directly received by the 1st photodiode 3a, and is reduced compared with the light quantity of the reflected light which also contains a polarization component.

The second photodiode 3b generates an output current Db that changes according to the reduced amount of received light. As described above, in the case of the counterfeit banknote, the reflected light in the banknote 1 includes surface reflected light, that is, a large amount of polarized components, so that the output current Db decreases by the amount of polarization and is considerably smaller than the output current Da.

The output currents Da and Db in the first and third photodiodes 3a and 3b are converted into voltages in the first and second current / voltage change circuits 5a and 5b, respectively, and then differentially amplified. Is applied to the circuit 6. Then, the output voltage of the circuit 6 corresponding to the deviation X (= Da-Db) of the output currents Da, Db is compared with the discrimination reference voltage Vs in the voltage comparison circuit 7. As described above, the output current Da indicating the amount of reflected light received without passing through the polarization filter 4 and including the polarization component and the output current Db indicating the amount of reflected light from which the polarization component received through the polarization filter 4 has been removed. The deviation x of is greater for counterfeit bills that are richer than real banknotes that lack gloss. Therefore, the output voltage in the circuit 6 which shows this deviation x takes a small value with respect to a real banknote, and a big value with a counterfeit bill.

Since the discrimination reference voltage Vs is set to the intermediate value of both, the output of the comparison circuit 7 is the L level representing the real banknote when the real banknote is put into the vending machine, and the H level of the counterfeit banknote in the case of the counterfeit currency. It becomes In this way, the output of the comparison circuit 7 takes different levels depending on when the real banknote is inserted and when the counterfeit banknote is inserted to indicate the authenticity of the banknote.

As known in the art, the control device of the vending machine operates normally when the real banknote is inserted with reference to the output level of the comparison circuit 7, while the counterfeit currency is half-turned outside the vending machine when the counterfeit money is inserted. .

Referring to Fig. 3, a banknote identification device according to a second embodiment of the present invention will be described.

The apparatus of this embodiment differs from the apparatus of the first embodiment in that the division circuit 8 is used instead of the differential amplifier circuit 6, and the other configurations are the same. That is, in this embodiment, the authenticity of the banknote 1 is discriminated according to the ratio of the two rather than the deviation of the amount of the reflected light received through the polarization filter 4 of the amount of the reflected light received without passing through the polarization filter 94. have.

In detail, the polarization component received through the polarization filter 4 and the output current Da of the first photodiode 3a indicating the amount of reflected light including the received polarization component without passing through the polarization filter 4 The output current Db of the second photodiode 3b representing the amount of reflected light removed is two input terminals of the division circuit 8 via the first and second current / voltage change circuits 5a and 5b. The output voltage in the division circuit 8, which is applied to the respective circuits and represents the ratio x '(= Da / Db) of both output currents, is compared in the voltage comparison circuit 7 with the discrimination reference value Vs'.

As described above, the deviation of the output currents Da and Db is relatively small compared to the case where the banknote 1 lacks the gloss and the light amount of the surface reflection light (corresponding to the polarization component of the reflection light) is small, rich in the gloss and surface reflection light. In the case of many of these counterfeit bills. Therefore, the ratio x '(= da / db) of the positive output current is larger than 1 when the banknote 1 is a real banknote, and close to 1, and considerably larger than 1 when the banknote 1 is a fake banknote. The discrimination reference value Vs' is set to the intermediate value of both, and the voltage comparison circuit 7 generates an output signal indicating the authenticity of the bill by taking the L level in the case of a real bill and the H level in the case of a counterfeit bill.

4 to 6, a banknote identifying apparatus according to a third embodiment of the present invention will be described.

The apparatus of this embodiment uses a polarization filter freely disposed on the propagation path of one photodiode and reflected light instead of two photodiodes and a polarization filter disposed in front of one of them compared with the first embodiment. The point is mainly different.

As shown in FIG. 4, the banknote identifying device receives light from the light emitting diodes 2 incident on the banknote 1 at the incident angle α and is reflected by the banknote 1 at the reflection angle β to output an output current according to the received light amount. The photodiode 3 'for generating is provided, and is fixed to the movable part of the solenoid 9, on the propagation path of the reflected light, and the first position in front of the photodiode 3' (indicated by the dotted line in FIG. 4). ) And the polarization filter 4 'which is free to move between the 2nd position (shown by the solid line in FIG. 4) withdrawn from the propagation path of the reflected light.

As shown in FIG. 5, the output terminal of the current / voltage change circuit 5 'whose input terminal is connected to the output terminal of the photodiode 3' is connected to the input terminal of the A / D converter 11, and A The output terminal of the / D converter 11 is connected to a central processing unit (not shown) of the microcomputer via the buffer 2 and an input circuit (not shown) incorporated in the microcomputer 13. The microcomputer 13 preferably constitutes a part of a machine control device such as a vending machine equipped with a banknote identification device, and provides a memory (not shown), an output circuit, and the like. And the first and second drive circuits 14 and 15 for driving the solenoid 9, respectively.

The operation of the banknote identifying device of the third embodiment will be described below.

When the banknote 1 is conveyed to a predetermined position in the banknote identifying apparatus shown in FIG. 4 and temporarily held at the position, the microcomputer 13 starts a process for determining the authenticity of the banknote shown in FIG. . The microcomputer 13 first drives the solenoid 9 via the second driving circuit 15 to display the polarization filter 4 'in the second position shown by the solid line in FIG. After moving toward the position of < RTI ID = 0.0 > 1, < / RTI > the light emitting diode 2 is turned on via the first driving circuit 14, and the software timer T is reset and improved (step S1).

As a result, the light irradiated from the light emitting diode 2 and reflected by the banknote 1 is received by the photodiode 3 'via the polarization filter 4'. The output current of the photodiode 3 ', which represents the light amount of the reflected light from which the polarization component is removed by the polarization filter 4', is converted into a voltage in the current / voltage conversion circuit 5 'and then A / D converter 11 Is applied to.

In this state, the microcomputer 13 determines whether the timer T has timed up (step S2). The timer T times up, and thus the movement to the first position of the polarization filter 4 'is completed. If it is determined that the fluctuations in the output current of the photodiode 3 'due to the movement have disappeared, the microcomputer 13 sends an A / D conversion command to the A / D converter 11 (step S3). In response to this command, the A / D converter 11 converts the analog output voltage from the circuit 5 'into a digital signal Db' of a predetermined number of bits, and the butter 12 temporarily stores this data Db '. Next, the microcomputer 13 stores the data Db 'read from the buffer 12 in the built-in memory (step S4), and then turns off the solenoid 9 via the second drive circuit 15 and at the same time the second Software timer T 'is reset and started (step S5).

The second timer T 'is timed up, so that the polarization filter 4' completes the retraction from the first position indicated by the dotted line in FIG. 4 to the second position indicated by the solid line, and the filter ( If it is determined in step S6 that the variation of the output current of the photodiode 3 'according to the movement of 4') is controlled, the microcomputer 13 sends an A / D conversion command to the A / D converter 11 ( Step S7), data Da ', which is received by the photodiode 3' and indicates the amount of reflected light including the polarization component, is read from the butter 12 and stored in the memory (step S8), and the first drive circuit ( The light emitting diode 2 is turned OFF via 14) (step S9).

Xs)이면 진짜 지폐를 나타내는 호를 출력하고, 부정이면 위조지폐를 나타내는 신호를 출력한다(스텝 S12, S13). 예를 들면, 마이크로 컴퓨터(13)은 스텝 S11에서의 판별결과, 즉 지폐의 진위를 나타내는 값1 또는 0을 내장된 플래그 레지스터에 세트한다.Next, the microcomputer 13 subtracts the data Db 'from the data Da' and calculates the difference X (= Da'-Db ') (step S10), and this deviation X is the value in the first embodiment. It is determined whether it is equal to or smaller than Xs corresponding to Vs (step S11). For the reason explained in the first embodiment, the deviation X takes a small value if the banknote 1 is a real banknote and a large value if the banknote 1 is a fake banknote. Therefore, the microcomputer 13 confirms that the discrimination result in step S11 is positive (X

Xs) outputs an arc representing a real banknote, and if negative, outputs a signal representing a counterfeit bill (steps S12, S13). For example, the microcomputer 13 sets the discrimination result in step S11, that is, a value 1 or 0 indicating the authenticity of the bill in the built-in flag register.

The present invention is not limited to the above first to third embodiments, and various modifications are possible.

For example, although the color of the light source 2 was not specifically designated in the said embodiment, the color (for example, blue) of the site | part to which the light of the banknote 1 is irradiated, the auxiliary color, or the color close to this (for example, , Red) light may be irradiated. In this case, the degree of reflection on the surface of the banknote 1 does not depend so much on the light emission color of the light source 2, while the degree of reflection on the inside of the banknote which absorbs light of the color of the banknote and the auxiliary color well is reduced. Therefore, when the color of the banknote and the auxiliary color or the light of the color is irradiated, the amount of reflected light when received through the polarization filter to remove the polarization component and the amount of reflected light received without passing through the polarization filter and including the polarization component The difference is largely due to counterfeit bills, which have abundant luster, which include a large amount of surface reflected light (polarization component) in the reflected light, and real papers, which have a low contribution of surface reflected light due to a lack of luster. By generating the auxiliary color in this way, the authenticity of the banknote becomes easier.

In the above embodiment, the amount of light received when a polarizing filter is interposed on the propagation path of reflected light in one portion of the banknote 1 and the amount of light received when no polarizing filter is interposed, or the ratio of both, In other words, the authenticity of a banknote was determined based on whether the glossiness of one part of the banknote matches the glossiness of the corresponding part of the banknote, but it is determined whether the gloss pattern of the banknote matches the gloss pattern of the real banknote. The authenticity may be determined. In this case, deviations or ratios of the two types of light received amounts are detected for each of the various portions of the banknotes, these deviations or ratios are compared with respective determination reference values set in advance, and the authenticity of the banknotes is determined according to these comparison results. do.

In the above embodiment, one kind of genuine banknote is made identifiable by various counterfeit bills, but the embodiment can be modified to be identifiable with respect to various kinds of genuine banknotes. In this case, the type of the real banknote is discriminated by a conventionally known method, such as detecting the bill size by an appropriate sensor system, and according to the discrimination result, the second number of the same number as the number of the real banknotes is prepared and set different discrimination reference values. One corresponding to the circuit portion as shown in FIG. 3 or FIG. 3 is connected to the two light receiving elements. Alternatively, the discrimination reference value Xs in step S11 of FIG. 6 is set to a value according to the discrimination criterion.

In the above embodiment, the case where the real money and the counterfeit money in which the color is copied is mainly described is described, but according to the present invention, various counterfeit money in which the gloss and the gloss of the real money are different can be identified from the real money. In addition, although a light emitting diode is used as a light source and a photodiode is used as a light receiving element, various light sources and light receiving elements can be used.

In the above first and second embodiments, the authenticity of the bills was determined by comparing the difference or ratio of the output currents of the two light receiving elements with the discrimination reference value in the analog circuit. This determination may be performed by digital processing according to the digital data to be shown. Further, in the third embodiment, it is discriminated according to the difference of the light receiving element output current when it is received through the polarization filter and when it is received without the polarization filter, but as in the second embodiment, You may discriminate according to the ratio of output current.

Claims (20)

(a) irradiating light to a banknote at a predetermined angle of incidence, (b) detecting a light amount of reflected light in the banknote including a component polarized upon reflection on the surface of the banknote, (c) the polarization component The degree of gloss on the surface of the banknote is detected according to the step of detecting the light amount of the reflected light from which the light is removed and (d) the amount of reflected light detected in the steps (b) and (c), respectively. Banknote identification method comprising the step of discriminating. The bill discrimination method according to claim 1, wherein the step (d) is discriminated in accordance with the deviation of the light reception amount in the step (b) and the light reception amount in the step (c). The degree of gloss of the surface of the banknote as defined in claim 2 when the deviation is greater than the predetermined discrimination reference value by comparing the deviation with a predetermined discrimination reference value in the step (d). Banknote identification method to determine the counterfeit bill larger than the degree of. The bill discrimination method according to claim 1, wherein the step (d) is discriminated in accordance with the ratio of the light reception amount in the step (b) to the light reception amount in the step (c). 5. The glossiness of the surface of the banknote as described in claim 4, wherein when the ratio is larger than the predetermined discrimination reference value by comparing the ratio with a predetermined discrimination reference value in the step (d), Banknote identification method to determine the counterfeit bill larger than the degree of. The bill identification method of any one of Claims 1-5 which irradiates the color of the site | part to which light of the said banknote is irradiated in the said step (a), light of an auxiliary color, or a color close to this. A light source 2 for irradiating light to the banknote 1 at a predetermined angle of incidence, and a first light receiving element arranged to be capable of directly receiving the reflected light from the paper and generating a first electric signal that changes according to the amount of received light; 3a) a second light receiving element 3b disposed so as to receive the reflected light and generating a second electric signal that changes according to the amount of reflected light received through the polarization filter, between the banknote and the second light receiving element The degree of glossiness of the surface of the banknote according to the polarization filter 4 and the first and second electrical signals for removing components of the light polarized upon reflection on the surface of the banknote and disposed on the propagation path of the reflected light And discriminating means for detecting the authenticity of the banknote. 8. The bill identifying apparatus according to claim 7, wherein the light source (2) is a light emitting diode, and the first and second light receiving elements (3a, 3b) are two photodiodes formed adjacent to one chip. The method of claim 7, wherein the discriminating means comprises: a first circuit 6 for detecting a deviation of the first and second electrical signals and a second circuit for comparing the deviation and a discrimination reference value. Banknote identification device containing (7). The bill discrimination apparatus according to claim 9, wherein the discriminating means discriminates that the degree of gloss on the surface of the bill is greater than the degree of gloss of the real bill when the deviation is greater than the discrimination reference value. 8. A claim 8 according to claim 7, wherein the discriminating means comprises a first circuit 8 for detecting the ratio of the first and second electrical output signals and a second circuit for comparing the ratio and the discrimination reference value. Banknote identification device containing (7). The bill discrimination apparatus according to claim 11, wherein the discriminating means discriminates that the degree of gloss on the surface of the bill is greater than the degree of gloss of the real bill when the ratio is greater than the discrimination reference value. The said light source is a banknote identification device of any one of Claims 7-12 which irradiates the light of the color of a site | part irradiated with the light of the said banknote with an auxiliary color, or a color close to this. A light source 2 for irradiating light to a banknote at a predetermined angle of incidence, a light receiving element 3 'for receiving the reflected light from the banknote, and generating an electric signal that changes according to the amount of light received, between the banknote and the light receiving element Movement is freely disposed between the first position interposed on the propagation path of the reflected light and the second position withdrawn from the propagation path of the reflected light, so as to remove components of the polarized light upon reflection on the banknote surface. An actuated polarization filter 4 ', drive means 9 and 15 for moving the polarization filter between the first and second positions and the polarization filter may take the first and second positions. Wherein each occurrence company comprises discriminating means for detecting the degree of glossiness on the surface of the banknote in accordance with the electric signal, thereby determining the authenticity of the banknote. The bill identifying apparatus according to claim 14, wherein the light source is a light emitting diode and the light receiving element is a photodiode. The bill discrimination apparatus according to claim 14, wherein said discriminating means performs discrimination in accordance with the difference of each output from said light receiving element when said polarizing filter takes said first and second positions. The bill discrimination apparatus according to claim 14, wherein said discriminating means performs discrimination in accordance with a ratio of respective outputs from said light receiving element when said polarizing filter takes said first and second positions. The method according to claim 15, wherein the discriminating means comprises: a first conversion circuit 5 'for converting an output current from the photodiode into a voltage, and the polarization filter has taken the first and second positions. The difference between the second conversion circuit 11 for converting the output voltage of the first conversion circuit into digital data at the time and temporarily storing the data, and the two digital data sequentially read from the second conversion circuit. And information processing means (13) for calculating any one of a ratio and a ratio and comparing it with a discrimination reference value. 19. The counterfeit bill according to claim 18, wherein the information processing means has a degree of gloss on the surface of the banknote greater than that of a real banknote when any one of a difference and a ratio of the digital data is larger than the discrimination reference value. Banknote identification device to discriminate. The bill identification device according to any one of claims 14 to 19, wherein the park irradiates light of a color and an auxiliary color of a portion to which the light of the bill is irradiated, or a color close to the same.

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